Apparatus for lifting and aligning building material



April 15, 1969 G. D. BOSE ET AL 3,438,514

APPARATUS FOR LIFTING AND ALIGNING BUILDING MATERIAL Sheet Filed May 22,1967 INVENTORS.

Gaeaou 0 505:- We 7'00 E. 6052 ATTQ A/t-YS United States Patent US. Cl.2141 7 Claims ABSTRACT OF THE DISCLOSURE A powered lift for elevatingsheetrock or the like to a substantially horizontal position adjacent aceiling. The device includes a frame having vertically extending,telescoping sleeves and a motor mounted thereon, with the motor drivingthe inner sleeve through a screw jack connection for elevating the innersleeve relative to the outer sleeve. The inner sleeve has a materialsupporting structure movably secured to the upper end thereof, andresiliently biased to a substantially horizontal position by a pluralityof spring elements. The spring elements are yieldable to permit amonoplanar sheet of building material carried by the supportingstructure to be depressed from a horizontal plane by a force actingdownwardly on the sheet at any point on its upper surface.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to devices used for the purpose of elevating building materialsto a location adjacent a ceiling so that such materials can be attachedor secured to the ceiling with a minimum of difliculty. More particu-Brief description of the prior art A number of jacks, hoists andelevating devices have heretofore been proposed for permitting acarpenter to mechanically elevate a large and heavy sheet of buildingmaterial, such as sheetrock or wall board, from approximately floorlevel to a position adjacent a ceiling to which such building materialsare to be secured. Many of these devices include supporting platforms orstructures upon which the sheet of building material is initially placedin a horizontal position. The supporting structure is then mechanicallyraised by a screw jack, or a hydraulic lift of some type, or othersuitable device, until the horizontally extending sheet is pressedagainst, or is immediately adjacent, the rafters or other ceilingsubstructure to which the sheet is to be secured.

Frequently, particularly in older houses, the ceilings are not preciselyhorizontal, or are not in exact parallelism with the floor. In someother structures, the ceilings are characterized in having imperfectionsin the manner in which the rafters or lathing are constructed 50 thatthe sheetrock or other finishing material must be warped or bent to someextent in order to accommodate it to the ceiling. Where buildings havingdefects or non-uniformities of the type described are encountered, thesheetrock or building material lifts heretofore provided present somedifficulty in use. This is due to the fact that, in almost everyinstance, the apparatus provided is constructed so that the sheetrock orother monoplanar sheet of building material is raised upwardly in aposition in which it occupies a plane extending substantiallyhorizontally with respect to the floor. In such situations, it isnecessary for the carpenter or sheetrock craftsman to bodily fit thesheetrock to the ceiling which is defeotively constructed, or is forsome reason, out of precise parallelism with respect to the floor. Thus,it may be necessary for the carpenter to manually lift one side of theesheetrock off of the supporting structure of the elevator in order tolift it up to the ceiling after it has been secured along one edge tothe ceiling, or he may have to exert considerable manual force to bendthe sheetrock to the contour of the ceiling.

Brief description of the present invention The present inventionprovides an improved apparatus for elevating monoplanar sheets ofbuilding material to a position in which they can be easily and quicklysecured to a ceiling or other overhead structure. The improvement in theapparatus of the invention is felt to reside primarily, though notexclusively, in the provision in the apparatus of means which permitsthe sheet of building material to be firmly supported from below despitethe necessity to elevate or depress one or more corners or portions ofthe sheet as it is installed on the ceiling. Broadly described, theapparatus of the present invention comprises a frame, a pair ofvertically extending, telescoping members mounted on the frame, amaterial supporting structure secured to the upper end of one of thetelescoped members, a prime mover supported on the frame, and meansdrivingly connecting the prime mover to one of the telescoped membersfor elevating said one telescoped member relative to the othertelescoped member. The material supporting structure includes aplurality of vertically extending, spaced rigid support elements, aplurality of horizontally extending, spaced support elements, andresilient means supporting the horizontally extending support elementson the vertically extending support elements. The horizontally extendingsupport elements can thus move relative to the remainder of theapparatus to accommodate necessary departures from a true horizontalplane of substantially monoplanar building materials rested on, andsupported by, the material supporting structure.

In a preferred embodiment of the invention, a motor or other prime movermounted on the frame drives one of the telescoping members in verticalreciprocating movement through a screw jack mechanism in which athreaded shaft driven in rotation by the prime mover engages a threadednut secured to, and movable with, the telescoping member which is to beelevated by actuation of the prime mover. It is also a preferredconstruction of the invention to make each of the telescoped memberstubular in construction and to extend the shaft of the screw jackmechanism concentrically in the inner tubular member to cause thismember to move upwardly within a surrounding tubular member, and by thismeans to elevate a material supporting structure secured to the upperend of the inner tubular member.

By the described construction, the carpenter is permitted to achieve amajor object to the present invention, i.e. the fitting andaccommodation, with a minimum of manual exertion, of sheetrock and othermonoplanar building materials to ceilings which are not in parallelismwith the floor, or which have local deformities or departures fromuniformity which require the sheet of building material to be adjustedin its position.

An additional object to the present invention is to pro vide a powerdriven, automatically operated apparatus for lifting sheetrock and thelike from a position relatively close to the floor to a location injuxtaposition to a ceiling to which the material is to be secured.

A further object of the invention is to provide an improved device forlifting, with a minimum of effort, a large, substantially monoplanarsheet of building material to a position of securement on a ceiling orother overhead structure in a building or the like.

A further object of the invention is to provide an apparatus for liftingsheet building materials to an overhead location, which apparatus isrelatively simple and inexpensive in construction, but which ismechanically strong and characterized in having a long and troublefreeoperating life.

Additional objects and advantages of the invention will become apparentas the following detailed description of the invention is read inconjunction with the accompanying drawings which illustrate theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a perspective view of oneembodiment of the lifting apparatus of the present invention.

FIGURE 2 is a plan view of the lifting apparatus of the invention.

FIGURE 3 is a section taken along line 33 of FIG- URE 2.

FIGURE 4 is a section taken along line 4-4 of FIG- URE 2.

FIGURE 5 is a section taken along line 55 of FIG- URE 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION In thefollowing detailed description of the invention in which reference ismade to the accompanying drawings, a combination referred to in thedescription which includes a plurality of subcombinations will :bedesignated in the drawings by a reference character having anarrowhead-carrying lead line associated therewith. Subcombinations whichinclude a plurality of elements will be de signated by underlinedreference numerals having plain lead lines, and individual elements ofstructure will be designated by reference characters which are notunderlined, and which are associated with plain lead lines having noarrowheads.

Referring now to the drawings in detail, and particularly to FIGURE 1,the lifting apparatus of the invention includes a main supporting framedesginated generally by reference numeral and including verticallyextending bars or rods 12 interconnected by horizontally extending upperrods 14 and horizontally extending lower rods 16. A pair of transverserods 17 extend between two of the horizontally extending lower rods 16.A generally H-shaped subframe designated generally by reference numeral18 is secured to the horizontally extending lower rods 16, and functionsto provide reinforcement for the frame and additional support for anelevating assembly hereinafter described. The subfr'ame 18 includes apair of horizontally extending end members 20 which are secured betweenthe vertically extending rods 12, and a pair of spaced paralleltransverse supporting rods 22 which are superimposed on, and welded orotherwise suitably secured to, the coextending transverse rods 17 weldedagetween two of the horizontal lower rods 16 of the main ffa rne.Disposed at the corners of the main frame and secured to the lower sideof the horizontally extending lower rods 16 are a plurality of casters26 which permit the lifting apparatus of the invention to be easilymoved from one location to another.

A support plate 30 is secured to the upper side of the spaced transversesupporting rods 22 of the subframe 18, and the support plate 30 is usedto support the weight of an elevating assembly designated generally byreference character 32. The elevating assembly includes, in theillustrated embodiment, an outer tubular member 34 which has its lowerend secured to the support plate 30, and an inner tubular member 36which is telescoped in the outer tubular member 34 and is axiallymovable with 4 respect thereto. Both of the tubular members 34 and 36are preferably rectangular or square in transverse cross section. Forthe purpose of further reinforcing the frame 10 and stabilizing theouter tubular member 34, a pair of parallel cross members 38 are securedbetween two op posed horizontally extending upper rods 14 of theframework 10 and bear against, and are secured to, opposite sides of theouter tubular member 34.

For the purpose of driving the inner tubular member 36 in verticalreciprocation with respect to the outer tubular member 34, an elongatedthreaded shaft 40 extends upwardly inside the inner tubu-lar member andis supported at its lower end in a thrust bearing 42 mounted on theupper side of the support plate 30. The lower end portion of thethreaded shaft 40 extends through an aperture 44 provided in the supportplate 30, and a sprocket 46 is keyed to the lower end ofthe threadedshaft below the support plate. A nut housing 48 is secured to theinternal walls of the inner tubular member 36 and closely surrounds andencloses a threaded nut 50 which engages the threads of the threadedshaft 40 but is prevented from rotating relative to the tubular member36 by reason of its close proximity to the nut housing 48. The nuthousing 48 also functions to limit the axial travel of the nut withrespect to the threaded shaft 40.

Near its upper end, the threaded shaft 40 carries a sleeve 52 whichcoaxially surrounds the shaft and is prevented from moving axially alongthe shaft by the pins 54. The sleeve 52 has secured thereto acircumferential flange 56 which extends outwardly to the walls of theinner tubular member 36 and thus, by virtue of the square or rectangularcross-sectional configuration of the inner tubular member, preventsrotation of the sleeve relative to the inner tubular member as thethreaded shaft 40 is driven in rotation. The sleeve 52 andcircumferential flange 56 thus function as a guide for retaining theupper end of the threaded shaft 40 in alignment with respect to theinner tubular member 36 during the operation of the device ashereinafter described.

For the purpose of driving the threaded shaft 40 of the elevatingassembly 32 in rotation about its longitudinal axis, a reversible motor60, or other suitable prime mover, is mounted on the frame 10 by anysuitable means, and, in the illustrated embodiment, is shown as boltedto a vertically extending plate 62 which is welded to the transversesupporting rod 22 of the subframe 18. The vertically extending plate 62is braced by a diagonal bar or rod 64 which extends from the upper edgeof the plate to a horizontally extending lower rod 16 of the frame 10.The motor carries a sprocket (not visible) which is drivingly connectedby a suitable chain 66 to the sprocket 46 on the lower end of thethreaded shaft 40. A switch 68 utilized to close an electrical circuitto deliver power to the motor 60 can conveniently be mounted on theframe 10 in the manner depicted in FIGURE 1.

A material supporting structure designated generally by referencecharacter 70 is secured to the upper end of the inner tubular. member 36for vertical reciprocation therewith. The material supporting structureincludes a horizontally extending rectangular plate 72 which is weldedor otherwise suitably secured to the upper end of the inner tubularmember 36. Secured along two parallel edges of the plate 72 are a pairof parallel bars or rods 74 which bracket or pass on opposite sides ofthe outer tubular member 34 when the inner tubular member 36 is loweredto move the material supporting structure 70 I to the position depictedin FIGURES 1 and 3. Secured to the opposite ends of each of the bars 74are upwardly extending bars or rods 76 of relatively small diameter (seeFIGURE 4). A pair of relatively large diameter tubular members 78 aretelescoped over the rods 76 located at each end of each of the bars 74,and are yieldingly retained in spaced axial relation with respect to therods 76 by a helical spring 80 or other resilient element in the mannerdepicted in FIGURE 4. Thus, where the helical springs are used, thesesprings can be placed around the rod 76 and extended upwardly beyond thefree end thereof.

At its upper end, each of the tubular members 78 is secured to ahorizontally extending material supporting runner 82, so that two ofthese runners extending in parallelism are provided and afford supportfor a monoplanar sheet of building material rested thereon. The materialsupporting runners 82 are also connected by support elements 84 whichextend parallel to each other and horizontally between the runners (seeFIGURE 2). It will be noted in referring to FIGURES 2 and 4 that theconstruction of the material supporting structure 70 is such that amonoplanar sheet of building material may be firmly supported upon therunners 82 and cross members 84, which are in turn supported upon therods 76 by the springs 80. The springs, however, resiliently andyieldingly mount the runners 82 and cross members 84 so that, if itshould be desired to depress the sheet of building material from ahorizontal plane to accommodate it to a ceiling which is out ofparallelism with the floor, or in some way distorted, such realignmentor repositioning of the sheet of building material can be accomplishedmerely by depressing the one side or corner of the building material toachieve the position sought.

OPERATION In utilizing the lifting apparatus of the invention forelevating the sheet building materials to a location adjacent a ceilingto which they are to be secured, the carpenter first moves the apparatusto the desired location by pushing on the frame 110 to cause theapparatus to roll on the casters 26. In some instances, it may bedesirable to move the shcetrock or other building material with thelifting apparatus, and in this case, prior to moving the apparatus inthe manner described, the sheet of building material is raised upwardlyand positioned on the runners 82 and cross members 84 of the materialsupporting structure 70. This is accomplished, of course, at a time whenthe motor 60 has been energized to drive the threaded shaft 40 in adirection which lowers the inner tubular member 36 and the supportingstructure carried thereby to its lowermost position as depicted in thedrawings.

When the lifting apparatus has been moved to a posi- 4 tion below theportion of the ceiling to which the sheet of building material is to beattached, the reversible motor 60 is energized to drive the shaft 40 ina rotational direction such that the inner tubular member 36 is movedupwardly by its engagement with the shaft 40 through the nut 50. Theinner tubular member 36 can move freely with respect to the outertubular member 34, and upward movement of the inner tubular member canbe continued until the nut housing 48 strikes the retaining pin 54 nearthe upper end of the threaded shaft 40. At or prior to this time, thematerial supporting structure 70 secured to the upper end of the innertubular member 36 will have been moved into juxtaposition to theceiling, and the sheet of building material carried thereby will eitherflatly abut the ceiling, or at least a portion of the building materialwill contact the ceiling.

In the event that the ceiling does not extend parallel to the floor uponwhich the lifting apparatus is supported, or in the event of a localnon-uniformity in the ceiling, the sheet of material can nevertheless bepressed into fiat abutting relationship to the rafters or lathing bycontinuing to elevate the material supporting structure 70 for a slightdistance. As one portion of the sheet of building material contacts theceiling under these circumstances, its movement will be arrested and theresult will be that that portion of the runners 82 which supports thispart of the sheet material will also be arrested and one or both of therunners will be depressed with respect to the rods 76 by distortion ofthe helical springs 80. This adjustability inherent in the liftingapparatus of the prescut invention overcomes a difficulty which has beenexperienced by carpenters and craftsmen in using sheetrock lifts andother structures as previously constructed for the purpose of securinglarge, substantially monoplanar sheets of building materials to aceiling.

From the foregoing description of the invention, it will have becomeapparent that the present invention provides an improved liftingapparatus for lifting or elevating sheets of building material from thefloor or other relatively low level to a position adjacent a ceilingwith a minimum of manual manipulation being involved in locating thematerial at the precise position where it is to be secured to theceiling. The apparatus is relatively inexpensive to construct, hasrelatively few moving parts, and is characterized in having a long andtrouble-free life.

Although a preferred embodiment of the invention has been described inthe foregoing specification and illustrated in the drawings, manychanges and innovations can be effected in the described and depictedstructure without departure from the basic principles of the invention.Changes of this type which continue to rely upon these principles aredeemed to be circumscribed by the spirit and scope of the inventionexcept as the same may be necessarily limited by the accompanying claimsor reasonable equivalents thereof.

We claim:

1. Lifting apparatus comprising:

a frame;

an elevating assembly mounted on said frame and including a verticallyextending member movable in vertical reciprocation relative to saidframe;

a prime mover mounted on said frame and drivingly connected to saidelevating assembly for moving said member upwardly and downwardlyrelative to said frame;

a material supporting structure secured to the upper end of saidvertically extending member and including material supporting runners;

a plurality of horizontally spaced, vertically extending rods mountedatop said vertically extending member;

spring guide means on said runners aligned with said rods; and

a plurality of springs positioned between said rods and spring guidemeans and resiliently spacing said runners above said rods.

2. The lifting apparatus defined in claim 1 wherein said elevatingassembly is further characterized to include a second verticallyextending member telescopingly engaging said first vertically extendingmember and connected to said frame.

3. The lifting apparatus defined in claim 2 wherein said telescopedmembers are tubular, and said elevating assembly is furthercharacterized as including:

a threaded shaft extending upwardly inside the innermost of saidtelescoped tubular members and connected to said frame;

a nut threadedly engaging said shaft and connected to saidfirst-mentioned vertically extending member; and

means connecting said prime mover to said shaft for driving said shaftin rotation when said prime mover is energized.

4. The lifting apparatus defined in claim 3 wherein said spring-guidemeans comprises a plurality of tubular members corresponding in numberto said rods and each extending over and around one of said rods, andwherein said means including said rods comprises:

a substantially horizontal plate secured to the upper end end of saidfirst-mentioned vertically extending memher; and

horizontally extending bars secured to said plate and each having aplurality of said vertically extending rods secured thereto.

*5. The lifting apparatus defined in claim .1 'wherein said spring-guidemeans comprises 7 a plurality of tubular members corresponding in numberto said rods and each extending over and around one of said rods; andwherein said means including said rods comprises:

a substantially horizontal plate secured to the upper end of saidvertically extending member; and

horizontally extending bars secured to said plate and each having aplurality of said vertically extending rods secured thereto.

6. Apparatus for elevating substantially monoplanar sheets of buildingmaterials While such sheets are horizontally positioned comprising:

a pair of telescoped tubular member having one of said members movablevertically relative to the other of said members;

a threaded rod extending inside the innermost of said pair of tubularmembers;

av nut threadedly' engaging said rod and connected to said one member;

means for rotating said rod;

a plurality of spaced, horizontally extending, substantially parallelbars mounted on the upper end of said vertically reciprocating memberfor vertical reciprocation therewith;

a plurality of runner elements spaced vertically from said bars and eachextending in a generally horizontal direction;

a plurality of horizontally spaced springs positioned between saidrunner elements and bars to resiliently support said runner elements onsaid bars;

a pair of horizontally spaced, vertically extending rods on each of saidbars and each concentrically surrounded by, and providing alignment for,one of said springs; and

spring guide means on each of said runner elements receiving andaligning said springs with said runner elements.

7. Lifting apparatus comprising:

a frame;

an elevating assembly mounted on said frame and including a verticallyextending member movable in vertical reciprocation relative to saidframe;

means mounted on said frame for vertically reciprocating said verticallyextending member relative to said frame; and

a material supporting structure secured to the upper end of saidvertically extending member and includmg a horizontally extending platesecured to the upper end of said vertically extending member and movabletherewith;

a plurality of rods secured to said horizontally extending plate andprojecting horizontally therefrom;

material supporting runners spaced vertically above said rods; and

resilient means yieldingly supporting said runners at four spacedpoints, and extending between said runners and said rods at locations onsaid rods spaced from said horizontally extending plate. ReferencesCited UNITED STATES PATENTS 2,574,857 11/1951 Ball Z1495 2,910,88311/1959 Reed 25410 3 XR 2,964,293 12/1960 Foth. 3,083,948 4/1963Goldfader 254103 XR FOREIGN PATENTS 661,682. 11/ 1951 Great Britain.

a GERALD M. 'FO'RLENZA, Primary Examiner.

F. 'E. WERNER, Assistant Examiner.

